Guanidinium Hydrogen Squarate

The unit cell contains two crystallographically independent formula units, CH₆N₃⁺.C₄HO₄^-, that are connected via a three-dimensional network of hydrogen bonds. Two crystallographically independent anion-cation chains are formed and arranged in two crystallographically independent layers and stacked along the b axis. The guanidine molecule accepts a proton from the squaric acid. Anions and cations are nearly planar. In the anions, the C-O and especially the C-C bond lengths differ significantly and the C-C-C angles deviate significantly from 90°.

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